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When to Plant Watermelon in Jackson County, FL

Watermelon is a sprawling vine crop that produces sweet, juicy fruits in hot weather. Varieties range from personal-sized icebox types to 50-pound giants.

Jackson County, Florida is in USDA Zone 8b. The average last spring frost is March 6 and the first fall frost is November 19, giving you a growing season of approximately 258 days.

At an elevation of 223 feet, Jackson County receives approximately 48.5 inches of rainfall annually with predominantly sand soil. Summer highs average 92ยฐF, providing good warmth for Watermelon during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Watermelon will need more frequent watering and organic matter to retain nutrients.

Jackson County, FL (Zone 8b) Long season
258 days
Last Spring Frost March 6
258 growing days
First Fall Frost November 19

Jackson County Soil Profile

Soil Type

Sand

Soil pH

5.1-6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Jan 31 Transplant: Mar 14 🍅 Harvest: May 23 – Jul 11
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Feb 6 Transplant: Mar 20 🍅 Harvest: May 29 – Jul 17
Safe Start (90%) ✓ Fits season (130 days to spare)
Start indoors: Feb 27 Transplant: Apr 10 🍅 Harvest: Jun 19 – Aug 7

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Jackson County

How your county's soil matches Watermelon's growing requirements.

Soil pH

Your soil pH (5.1โ€“6.0) is more acidic than Watermelon prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Jackson County warms quickly in spring but drains fast. Watermelon will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Watermelon.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Watermelon.

How to Plant Watermelon

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Watermelon

4
successive plantings in your 258-day season

Sow every 8 weeks. Last sowing by Aug 11 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
1.4″/week
Watering frequency 2-3 times/week
Season total 3,198 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Watermelon

Watermelon needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watermelon Needs Rainfall You Supplement Action
Jan โ€” 2.3" 0" โ„๏ธ Dormant
Feb โ€” 2.6" 0" โ„๏ธ Dormant
Mar 6.5" 2.7" 3.8" ๐Ÿšฟ Regular watering
Apr 6.5" 1.9" 4.6" ๐Ÿšฟ Regular watering
May 6.5" 3.2" 3.3" ๐Ÿšฟ Regular watering
Jun 6.5" 7" 0" โœ… Rainfall sufficient
Jul 6.5" 7.2" 0" โœ… Rainfall sufficient
Aug 6.5" 7.5" 0" โœ… Rainfall sufficient
Sep 6.5" 6.1" 0.4" ๐Ÿ’ง Light watering
Oct 6.5" 4" 2.5" ๐Ÿ’ง Light watering
Nov 6.5" 1.9" 4.6" ๐Ÿšฟ Regular watering
Dec โ€” 2.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Jackson County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Watermelon Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Watermelon needs ~1,615 GDD — county provides 4,902 GDD Excellent fit

Watermelon Planting Timeline โ€” Jackson County, FL

Watermelon Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 โ€“ Feb 20
Transplant Outdoors March 20 Mar 20 โ€“ Apr 3
Direct Sow March 13 Mar 13 โ€“ Apr 3
Harvest May 29 May 29 โ€“ Jul 17

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

258 days in Jackson County

Growing Tips for Watermelon in Jackson County

Direct sow Watermelon outdoors after March 06 in Jackson County when soil has warmed and frost danger has passed.

Sandy soil in Jackson County dries quickly โ€” mulch Watermelon with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Watermelon in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 3-4 weeks early or direct sow after soil is warm. Plant on mounds with plenty of space. Check ripeness by looking for a yellow ground spot and dull thump when tapped.

Recommended Watermelon Varieties for Jackson County

Full-size melons that thrive with your long season

Crimson Sweet (85d) Charleston Gray (85d) Moon and Stars (95d)

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watermelon in Jackson County, FL?

Jackson County is in Zone 8b with an average last frost of March 6. Plan your Watermelon planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jackson County, FL?

Jackson County, Florida is in USDA Hardiness Zone 8b. The average last spring frost is March 6 and first fall frost is November 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jackson County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jackson County, FL. Local conditions may vary. Last updated: April 2026.